By TOM PAULSON, P-I REPORTER

Published 10:00 pm, Thursday, February 1, 2007

Four men in King County have tested positive for a similar strain of HIV that is highly resistant to drugs, public health officials said Thursday, raising the concern that others who had sex with them could also be infected with this aggressive and often untreatable infection.

"There may be more cases we don't know about," said Dr. Bob Wood, director of the HIV/AIDS program for Public Health -- Seattle & King County.

"We are still working to learn more about these individuals and the virus they have contracted," said Dorothy Teeter, interim director of the health department. "We are concerned for these individuals and their partners, and are continuing our investigation."

What's most concerning, added Wood, is that the virus identified in the four men is a similarly resistant genetic strain despite the fact that none of them reportedly had any contact with one another. All are gay men who used crystal methamphetamine and had many sexual partners, he said.

"This is mostly about behavior," said Wood, who is gay and has medically managed his own HIV infection for more than 20 years. "Men who have sex with men need to know that drug-resistant strains can and are being transmitted and may be much less treatable."

At least 100 King County residents still die of AIDS every year, Wood noted, yet unsafe sexual behavior has increased within certain segments of the local population -- most notably among drug-using members of the gay community.

"There's a lot of complacency," Wood said. "People need to know that some of these new infections may be impossible to treat."

Dr. Peter Shalit, a physician who cares for people with HIV/AIDS and directs HIV/AIDS research at Swedish Medical Center, said it's especially worrisome that four men with no known common relationship would all have the same strain of drug-resistant virus.

"That's highly unusual," Shalit said. Though it's too early to say, he said this could indicate that we have in the community a new strain of multidrug-resistant HIV that is more easily spread than previous drug-resistant strains.

"That's definitely a scary prospect," Shalit said.

Public health officials are working with the men and their health care providers to try to locate and test their sexual partners for HIV and drug resistance. In 2003, Seattle and King County was one of the first metropolitan areas in the U.S. to launch a surveillance program for multidrug-resistant HIV.

Wood and Teeter asked that physicians and other health care providers routinely test for drug resistance among anyone with a positive HIV test and report any cases of suspected multidrug-resistant strains. Officials recommend that sexually active, drug-using gay and bisexual men at exceptionally high risk for infection be tested every three months. Others in high-risk categories should be tested yearly.

Public health officials previously had identified 12 other cases of multidrug-resistant HIV in King County. But none of them was as highly resistant to anti- viral drugs as these four related cases. This new strain was first identified in a man in 2005 and in three other men last year.

None of the four men has experienced any symptoms, Wood said. However, experts are concerned about the possibility that drug-resistant HIV can progress to AIDS much faster than is the case with the typical HIV infection.

Drug-resistant HIV is not a new problem, Wood said, and there is no evidence yet to suggest this new strain is any more transmissible.

"But it's certainly a reminder that this can still be a deadly disease," he said.

HIV infection today is treated with a number of drugs to which the virus can develop resistance. The virus genetically mutates and "learns" how to better defend against the drug. People with HIV are able to keep the infection at bay by moving to a different drug regimen.